06/01/2012 11:45 am ET Updated Aug 01, 2012

Bloomberg's Soda Ban will Fall Flat

Mayor Michael Bloomberg may think he's helping to curb obesity in New York City -- where it has doubled among adults since 1997 -- with his new proposal to ban sugary drinks over 16 ounces. In actuality all he is doing is providing fodder for conservatives who have long warned against government encroachment in the healthcare arena.

But aside from the politics of individual freedom and government overreach, there is a far larger problem: Mr. Bloomberg's faulty premises.

Speaking via live video stream at the D: All Things Digital conference, Mr. Bloomberg explained that $4 billion is spent on obesity efforts every year in New York City, so the government has a legitimate role in not only making city dwellers healthier but also spending less taxpayer money due to unhealthy lifestyle choices.

But this ban isn't targeted at those responsible for government healthcare spending. It will be in place at every restaurant, deli, sporting event, and food cart. This will affect every person interested in purchasing soda who resides in -- or for that matter, even visits -- New York City, whether the city pays for their healthcare or not. What does a tourist from Canada or Virginia have to do with New York's obesity costs? This law will only heighten animosity toward government's vital role in promoting healthier lifestyle habits.

And when Mr. Bloomberg's efforts have been targeted more closely, they haven't fared much better. He's previously supported a state soda tax that died in the legislature, and tried restricting soda purchases for food stamp recipients, something federal regulators decried. But Mr. Bloomberg hasn't been entirely unsuccessful. His administration was able to force eateries to put calorie counts on menus. While the measure was approved -- it hasn't proven effective. Preliminary research has been inconclusive and unable to show that consumers are making healthier choices as a result; and even worse, according to one study, consumers purchased 106 more calories when they were listed on menus.

The study focused on low-income consumers who typically are more sensitive to price than calories. And to Mr. Bloomberg's credit, limiting soda sales to 16 ounce containers will have the effect of making it more expensive per ounce; which could possibly lead to lower soda consumption by those who are most price conscious -- low-income consumers who also happen to have a higher prevalence of obesity.

However it's still far too punitive. This makes soda more expensive for everyone who purchases it -- not just those who don't do a good job of limiting their consumption. Furthermore, Mr. Bloomberg hasn't produced any research showing the majority of soda consumed is done so outside the home, where the ban actually is in place. There's a reason for that -- he can't. More than half of one's soda consumption occurs at home, according to the CDC. Soda consumed at home is more likely to be purchased from grocery stores and bodegas (corner stores), which will be exempt from the soda ban. So how much of an impact can this soda ban really have on an individual's daily caloric intake or overall health? Not much.

I get it. Mr. Bloomberg wants to leave a lasting legacy of health promotion in New York City. His focus on smoking cessation led to smoking bans in the city's restaurants and public parks. And I hope he's equally successful in his obesity efforts too. But for a guy focused on promoting healthy eating, the approach is all wrong: He uses the stick far more than the carrot.